The long-term goal of this research project is to examine the functional improtance of neurotaransmitters (primarily dopamine and norepinephrine) in the central nervous system. The immediate objective is to utilize a cerebroventricular perfusing technique in cat brain to examine the dynamic properties of dopamine in the nigrostriatal pathway and to examine the actions pf drugs on this system. The biochemical properties of5-hydroxytryptamine and possibly other putative neurotransmitters will be examined using the same techniques.